1. Field of the Invention
The present disclosure relates to a technical field of display, more particularly, to a chip on film and a display apparatus.
2. Description of the Related Art
With the development of the electronic and communication industry, demand for the flat panel display devices such as a light emitting diode (LED) and an organic light emitting diode (OLED), a plasma display panel (PDP) and a liquid crystal display (LCD) is increasing. The flat panel display devices have the development trend, for example, to become light, thin, short, and small-sized. The package techniques which have characteristics of high density, small volume, high mounting freedom degree or the like, are needed to meet the above requirements. Therefore, a chip on film (COF) package technique is developed.
The COF package technique is to fix a driver circuit onto a flexible circuit board, to use the flexible circuit board as a carrier for the package chip, and to combine the chip with the circuit of the flexible circuit board. As shown in FIG. 1, the existing COF arrangement includes a substrate 101, a driver circuit 102 fixed on the substrate 101, and an input end lead 103 and an output end lead 104 leaded out from the driver circuit 102. The input end lead 103 is electrically connected to a printed circuit board (PCB) with an anisotropic conductive film (ACF) by means of a pressing-jointing process. The output end lead 104 is electrically connected to pins on a glass substrate within the flat panel display with ACF by means of a pressing-jointing process, so that the PCB can transmit the driving signals to the respective signal lines within the flat display panel.
In the COF arrangement as described above, especially in the COF arrangement having a large bandwidth, the input end lead 103 or the output end lead 104 has a lager width in a direction as indicated by an arrow in FIG. 1. In this way, the surface of the input end lead 103 or the output end lead 104 tends to become uneven. In particular, after being attached with the ACF, the problem that the surface of the input end lead 103 or the output end lead 104 is bent, becomes more noticeable. As a result, generation of bubbles, docking offset or the like are created, after pressing the input end lead with the PCB or pressing the output end lead with the pins of the glass substrate within the display panel with ACE Therefore, they severely adverse the yield of the flat panel display devices.
Therefore, it is an urgent technical problem to be solved by the skilled person how to avoid defects of the display devices caused by unevenness of the surface of the input end lead or the output end lead.